905 nm雷达波段低折射率超透镜的仿真设计与研究  

Simulation design and research on low refractive index metasurface in 905 nm lidar band

作　　者：刘泽武 陈洁 郭程祥 杨磊[1] 谢洪波[1] LIU Zewu;CHEN Jie;GUO Chengxiang;YANG Lei;XIE Hongbo(Key Laboratory of Optoelectronics Information Technology(Ministry of Education),School of Precision Instruments and Optoelectronics Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密仪器与光电子工程学院光电信息技术教育部重点实验室,天津300072

出　　处：《红外与激光工程》2025年第3期270-280,共11页Infrared and Laser Engineering

摘　　要：基于超表面的激光雷达系统是当前的热门研究领域。现有的红外雷达波段超表面通常采用高折射率的TiO_(2)作为天线材料,这限制了超表面在CMOS兼容芯片上的集成。针对这一问题,研究采用低折射率材料Si_(3)N_(4)设计超表面的方法,采用熔融石英作为衬底、方形纳米柱作为纳米天线并保证了天线的低纵横比。使用有限差分时域仿真软件分析相同口径下不同焦距的超表面,并对比了它们的聚焦效率、传输效率和聚焦光斑大小随F数的变化,超透镜的聚焦光斑大小接近衍射极限,最大聚焦效率达到了80%。提出的设计方案适用于任意空间相位曲线的设计,有利于超表面与CMOS制造技术的兼容,对于实现超紧凑的芯片级激光雷达传感器具有参考意义。Objective Lidar systems based on metasurfaces are currently popular research topics.The development of lidar systems relying on traditional optical components has encountered a bottleneck,and the stacked optical component structure limits further miniaturization and integration.Recent advancements in metasurface research are seen as a promising alternative to traditional lidar technology.Metasurface-based lidar systems are expected to integrate lidar functionalities—such as light emission,scanning,and detection—into a single CMOS chip,paving the way for compact chip-level lidar sensors.However,existing infrared lidar-band metasurfaces typically use high refractive index materials,such as titanium oxide,as the antenna material,which limits their integration on CMOS-compatible chips.To address this issue,this paper explores the design of metasurfaces using CMOScompatible materials for the 905 nm lidar band.Methods Using the electromagnetic simulation software FDTD,we performed scans to determine the optimal period and antenna height for metasurfaces designed with the CMOS-compatible material silicon nitride.Additionally,we replaced cylindrical pillars with square posts to increase the antenna duty cycle.Furthermore,we simulated the performance of metasurfaces with different focal lengths under the same aperture,analyzing how their performance varied with the f-number.We also investigated the impact of dispersion on the focusing ability of the metasurfaces under broadband conditions.Results and Discussions Comparing the focusing performance of the metasurfaces with the same aperture but different focal lengths(Fig.5),it is evident that when the f-number of the metasurface is in the range of 0.6 to 5,the metasurfaces exhibits minimal focal length deviation,high focusing efficiency,and a resolution close to the diffraction limit.The broadband dispersion results of the metasurfaces(Fig.6)show that within the bandwidth and central wavelength shift range of the existing lidar source,the metasurface is able to achieve

关 键 词：光学设计 超透镜 衍射光学 激光雷达 SI3N4 

分 类 号：O436[机械工程—光学工程]